Lastly, we compare the performance of the tested algorithms on two discretization tensors of function data which were tested in [1]}. The ground truth tensor \({\cal T}_1\in \mathbb {R}^{n_1\times \cdots \times n_d}\)  is constructed by
\({\cal T}_1\left(i_1,\cdots ,i_d\right)= \exp \left(-\sqrt{\sum _{k = 1}^d \left(\frac{i_k}{n_k-1}\right)^2}\right),\) 
